Fatal cytomegalovirus pneumonia after preemptive antiviral therapy in a renal transplant recipient

Cytomegalovirus (CMV) infections occur with an incidence of up to 70% in renal transplant patients and mortality is low due to effective antiviral drugs. We report here the case of a patient who suffered from an uncommonly severe and therapy-resistant pulmonary CMV infection. During the disease course, CMV-PCR from alveolar cells and lung biopsy material was repeatedly negative despite high CMV pp65 antigenemia. CMV pneumonia was finally diagnosed from a biopsy obtained by open thoracotomy revealing positive CMV immunostaining of lung tissue. The patient died of respiratory failure though double-treatment using both ganciclovir and foscavir was administered. Post mortem, the clinically suspected resistance to both antiviral drugs, but not to cidofovir, could be proven by bioassay testing of in vitro growth responses using viral cultures. CMV pneumonia may thus not be diagnosed by standard PCR techniques in rare cases and may be resistant to the available antiviral therapy. Severe CMV pneumonia may benefit from novel antiviral drugs such as cidofovir, which is currently used in the treatment of CMV retinitis in HIV patients.